Probiotics have been defined as viable gastrointestinal bacteria that provide health benefits when consumed in adequate dietary amounts by a host, e.g., by a human or other mammal. Over a hundred years ago, Metchnikoff suggested that lactic acid bacteria and fermented yogurt could contribute to human longevity. With the ability to modify the bacterial flora found in the gastrointestinal tract, and to replace harmful microbes with benign and useful microbes, biologists have sought and found evidence of medical benefits provided by probiotic bacteria. Claimed benefits of probiotics include a decrease in potentially pathogenic gastro-intestinal bacteria, reduction in gastrointestinal bloating, strengthening of the immune system, improvement in bowel regularity, resistance to allergens, protection of cellular organelles and host DNA from oxidative damage, and restoring natural gut microbiota in subjects receiving antibiotic treatment. A widely cited review article by Soccol et al. (“The Potential of Probiotics: A Review,” Food Technol. Biotechnol. 48(4):413-34 (2010)) is useful in describing a wide variety of probiotic microorganisms, their function and their uses.
Probiotic bacteria have been added to a variety of solid, semi-solid and liquid food and beverage products containing varying amounts of nutrients and water. Such nutrients and water may or may not support the growth of these bacteria. Traditionally, freeze-dried preparations or hydrous forms of probiotic bacterial strains have been mixed with either an aqueous component such as a yogurt mixture or a fatty component of a food before being diluted and dispersed into the entirety of the food product. For example, probiotic margarines and table spreads have been described in the literature in which the fat content of the final food product may vary between 60% and 95% by weight, while the water content in the form of a water-in-oil (w/o) emulsion may range between 5%-40% by weight. In some instances, microencapsulation has been used to segregate probiotic bacteria from the water component in such spreads.
A study of the research literature shows that when probiotic bacteria are dispersed during or following the manufacture of a food product such as a fatty table spread, within a few months of storage either under refrigeration or at room temperature, a substantial loss in bacterial cell viability is detected. That is, colony forming units (CFUs) are significantly diminished over a period of months as evidenced, for example, by 10-, 100-, or even 1000-fold reduction in viable bacterial cell titers. (E.g., Klu et al., “Survival of Four Commercial Probiotic Mixtures in Full Fat and Reduced Fat Peanut Butter,” Food Microbiol. 44:34-40 (2014).) For example, an aqueous table spread containing probiotic bacteria has been described previously. However, the titers of viable bacteria were severely diminished both during manufacture and storage. (See Charteris et al., “Edible table (bio)spread containing potentially probiotic Lactobacillus and Bifidobacterium species,” Int'l J. Dairy Tech. 55(1):44-56 (2002).)
The present technology is directed to overcoming these and other deficiencies in the art.